That's self-defining. The client states are the ones that the US does not intervene in and the proof of it is that they don't intervene.

They've never intervened militarily in 95% of the world's countries including places like Bhutan, East Timor, the Central African Republic etc - are they all client states?

Egypt under the military dictatorship of hosni Mubarak was a US client state. The US propped Mubarak up with military and economic aid and political support for over 30 years, when the Arab spring hit Egypt the US stuck by their man until the last minute until it was clear that the democracy protesters would win and overthrow him and the US then threw Mubarak under the bus. Likewise in Bahrain the US sells Bahrain billions of $$$ worth of arms every year and won't lift a finger to help the democracy protesters in Bahrain because Bahrain is just another US Arab client state, ditto Yemen. As for Bhutan, east Timor and the central African republic, they don't have any oil or geopolitical importance to the US, hence they aren't client states.

Egypt under the military dictatorship of hosni Mubarak was a US client state. The US propped Mubarak up with military and economic aid and political support for over 30 years, when the Arab spring hit Egypt the US stuck by their man until the last minute until it was clear that the democracy protesters would win and overthrow him and the US then threw Mubarak under the bus. Likewise in Bahrain the US sells Bahrain billions of $$$ worth of arms every year and won't lift a finger to help the democracy protesters in Bahrain because Bahrain is just another US Arab client state, ditto Yemen. As for Bhutan, east Timor and the central African republic, they don't have any oil or geopolitical importance to the US, hence they aren't client states.

You have this entirely wrong. US aid to Egypt was part of the Camp David agreement that ended the conflict between Israel and Egypt. And Mubarak wasn't leader of Egypt back then. The USA criticised Mubarak (=sticking by their man), did nothing to help him, did nothing to unseat him and aid has continued.

Yemen has no oil and the US didn't intervene there = client state

Bhutan has no oil and the US didn't intervene there = not client state

You make it up as you go along.

Venezuela has oil and the US didn't intervene. So does Nigeria. Are they client states or are only Arab states ever client states?

You have this entirely wrong. US aid to Egypt was part of the Camp David agreement that ended the conflict between Israel and Egypt. And Mubarak wasn't leader of Egypt back then. The USA criticised Mubarak (=sticking by their man), did nothing to help him, did nothing to unseat him and aid has continued.

Yemen has no oil and the US didn't intervene there = client state
Bhutan has no oil and the US didn't intervene there = not client state

You make it up as you go along.

Venezuela has oil and the US didn't intervene. So does Nigeria. Are they client states or are only Arab states ever client states?

I can see you're struggling with what the definition of a client state is. Egypt first under Sadat then Mubarak was a Arab US client state, the US gave Egypt billions of dollars worth of military and economic aid and political support in return for a peace(surrender) deal with Israel and a peaceful stable middle east(no oil crisis). Yemen has oil but not to the degree of the Persian gulf countries but it does share a border with Saudi Arabia the US and UK's #1 friend in the region and both the US and Saudi Arabia can't have a non US aligned country on its border as it might catch on with their(Saudi) population, ditto Bahrain, Jordan, Kuwait etc. Also you've obviously never heard of the 2002 US supported coup against Venezuela's popular and democratically elected leader Hugo Chavez, who broke the domination of the foreign oil corporations, corporate America and the 1% in Venezuela and implemented policy changes so all of Venezuela's population could benefit from their oil wealth.

Yes, they benefit to the extent that they have no toilet paper. Venezuela squanders its vast oil wealth and runs a communist style economy with all its inefficiencies. And yes, I've heard of the coup but only the tinfoil hat brigade think that the USA had any real involvement. They didn't.

"Client state" is just simply circular nonsense. You seem to think that the USA brokering a peace deal between Egypt and Israel made Egypt into a "client state". Perhaps being at war is another characteristic of a non-client state in your world.

Yemen has oil to the extent that any country has oil. They have less than we do.